Chromium complexes of fluorocarbon acids



United States Patent Ofifice 2,693,458 Patented Nov. 2, 1954 CHROMIUM COMPLEXES OF FLUOROCARBON ACIDS Maynard H. Olson, St. Paul, Minn., assignor to Minuesota Mining & Manufacturing Company, St. Paul, Minn., a corporation of Delaware No Drawing. Application July 18, 1952, Serial No. 299,727

12 Claims. (Cl. 260-2) This invention relates to my discovery of a new class of chromium-containing fluorocarbon compounds, and polymers thereof, having novel and useful properties; and to materials which have been treated therewith so as to possess novel and useful surface properties. The polymers have a combination of water-repellency and oilrepel lency, resistance to acids, bases, reducing agents and oxidizing agents, thermal stability, and high electrical resistivity even at high humidities.

These new compounds are green-colored, tacky, liquid Werner-type coordination complexes of trivalent chromium and perfluoroalkyl monocarboxylic acids (normal and branched) that contain from 4 to 12 carbon atoms per acid molecule. These acids are fully fluorinated and have the generic formula CnF2n+1COOH, where n has a value of 3 to 11. These complexes contain chromium in its trivalent form and they contain two perfluoro acido groups bonded to each chromium atom. They contain no chlorine. The complexes and their polymers are very 1nsoluble in water. They contain more than 50% by weight of chemically combined (carbon-bonded) fluorine. The invention also embraces the ammoniated derivatives of these complexes and polymers.

Both the unammoniated and the ammoniated forms of the complexes can be heated to produce solid materials that are both water-repellent and oil-repellent (i. e., both hydrophobic and ol'eophobic), and that are insoluble in common non-polar organic solvents. The complexes can be. employed (either directly or in solution) for coating and impregnating a wide variety of materials and, upon heating, the substrate is provided with a coating that is both hydrophobic and ol'eophobic. This combination of hydrophobic and oleophobic' properties is due to the presence of fluorocarbon chains which contain at least three fluorinated carbon atoms. The heat-advanced solid products can be dissolved in suitable solvents and applied in solution form, evaporation of the solvent then leaving a. solid'coating.

The unammoniated liquid complex can be polymerized by heating toprovide a solid, non-tacky, non-thermoplastic, heat-stable material that is insoluble in nonflnorinated solvcnts;.bothpolar and non-polar, but which is soluble in highly fluorinated solvents. Self-sustaining flexible films and sheets, flexible coatings, and other products, can be made.

These Werner=type complexes are quite different from the ordinary trivalent-chromium salts of the acids, which are solids and contain three perfluoro acid groups per chromium atom.

The present class of complexes is to be distinguished from those that are made by reacting chromyl chloride (CrO'zClz) with a fluorocarbon acid in an inert anhydrous solvent vehicle (such as carbon tetrachloride), in the presence of a reducing agent (such as anhydrous methanol), and evaporating the reaction mixture to remove volatiles. tain two chromium atoms for each acido group. The complexes are green solid materials thatare slightly soluble in water (isufliciently so for coating purposes) and are highly soluble in. methanol and acetone. They contain chlorine. They can be heated in the presence of water to form water-repellent polymers, but HCl is released, which is sometimes disadvantageous when treating textile materials. Chromium complexes of that type are described and claimed in the copending application of T. S. Reid, Ser. No. 219,749, filed April 6, 1951, now U. S. Patent No. 2,662,835.

Such complexes and their polymers may coni In accordance with the present invention, the original unammoniated chromium complexes are formed by the reaction, in a system containing a hydroxylated compound, of a reactive compound containing trivalent chromium and containing no chlorine, and a perfluoroalkyl monocarboxylic acid that has from 4 to 12 carbon atoms in the molecule.

For example, the chromium complexes can be conveniently made by reacting together, in a 1:2 molar ratio, chromium trioxide (CrOs), which contains chromium in the hexavalent state, and a perfluoroalkyl monocarboxylic acid (CnF2n+1COOH) that has 4 to 12 carbon atoms in the molecule, in an aqueous reaction medium containing a reducing agent (such as methanol or isopropanol). The reducing agent reduces the chromium from a hexavalent to a trivalent state, and the reaction with the acid is effected with a reactive compound containing trivalent chromium. The use of an aqueous medium is greatly preferred for two major reasons: it reduces the fire hazard (chromium trioxide being a powerful oxidizing agent), and it causes the chromium-acid reaction product complex to precipitate out from the solution so that it can settle to form an immiscible lower layer which can easily be separated out and recovered in mechanical fashion. Heating is preferably employed to hasten the reaction and to minimize the eflect to competitive side reactions.

The chromium-complex reaction product is not a simple compound but is a liquid mixture of unpolymerized chromium-complex molecules (monomers) and polymerized molecules formed therefrom. Continued heating advances the extent of polymerization and changes the physical properties. During the initial period, the complex has a high solvent action for the perfluoro acid reactant and the reaction product contains dissolved acid in addition to the chemically bound perfluoro acido groups. As the reaction progresses (involving polymerization) the dissolved acid is released and reacts with the chromium trioxide to form fresh reaction-product com- (plex. The reaction goes to completion to produce a reaction product of exactly 2 moles of acid for each mole of chromium trioxide, the product containing 2 perfluoro acido groups for each chromium atom, the latter being in the trivalent state. Analytical evidence indicates that each monomeric molecule may contain a covalently linked hydroxyl group and a coordinatively linked water and/ or alcohol molecule (depending on the reaction medium).

Regardless of theory as to structure, the chromiumacid reaction product complex can be objectively defined as containing two perfluoro acido groups per chromium atom and as being a green-colored, water-insoluble, tacky, viscous liquid. it is thusly differentiated from the more highly polymerized end product which is a green-colored, water-insoluble, non-tacky, flexible, solid material. The latter will hereafter be referred to as the solid polymer or polymer product of the complex; the complex being the tacky liquid reaction product.

The initially formed water-insoluble complex is soluble in methanol (methyl alcohol) and other alcohols, acetone and other ketones, ethyl acetate and other esters, formalin, and is sparingly soluble in diethyl ether. It is not soluble in nonpolar solvents, such as carbon tetrachloride, heptane and benzene. This initial type of prodnot is of limited value since it contains dissolved acid which cannot easily be removed. The acid can be eliminated by heating but such heating advances the complex to a different state. If this initial acid-containing complex is recovered and used as such for providing coatings, which are set up to a solid state by heating, the dissolved acid will be wasted.

Further heating of the complex in the reaction vessel advances it to a methanol-insoluble state, eliminates the dissolved acid, and increases its viscosity. At this point the complex is considered to be in its final and most useful state. Although insoluble in normal (straight chain) alcohols, and sparingly soluble or insoluble in acetone, it is moderately and completely soluble 1n isopropanol (isopropyl alcohol), and solutions in the latter can be used for coating and impregnation purposes.

Still further heating of the liquid complex gradually destroys solubility even in isopropanol, that is, an increasingly large fraction of the material becomes insoluble in isopropanol owing to polymerization. However, the product remains in a tacky liquid state, becoming increasingly viscid. This viscid product becomes entirely isopropanol-insoluble before turning into the ultimate non-tacky solid polymer product.

All of these methanol-insoluble liquid complexes are soluble in highly fluorinated solvents. Examples of the latter are the fluorocarbons (carbon fluorides). the perfluoro aliphatic tertiary amines. and the perfluoro aliphatic and cyclic ethers. They are also soluble in Freon 12 (dichlorodifiuoromethane) and in Freon 113 (trifluorotrichloroethane) All of these liquid complexes will slowly but spontaneouslv polymerize to the solid state at room temperature. Heating at 190 C. or higher results in speedy polymerization (e. 2., the isopropanol-soluble complex will substantially fully polymerize in minutes at 130 C.). Solutions of the complexes can be u ed for coating or impregnating, or casting films. followed bv heating to remove residual solvent and form the solid polymer product.

The ultimate solid polymer product is a non-tacky, transparent, green-colored, non-thermoplastic, flexible ma terial, adapted to provide non-tackv films and surface coatings having a unique combination of useful properties. This solid polymer may contain less than a precisely 2:1 ratio of acido groups to chromium atoms. The polymer will stand prolonged heating without softer ing or decomposinsz. For instance. a sample film has been heated for 100 hours at 210 C. without softening or visible decomposition. However. some change did take place as shown by loss of weight. chance in X-rav pattern, and slight embrittlement. in another experiment, a film was heated on a brass block to a. temperature of 380 C. without appreciable softening or decomposition. This the mal stability is of reat value in respect to coatings and films used as insulation in electrical devices, such as motors and transformers, which can be designed to operate at hich temperatures. The polymer is insoluble in water and. in all common organic solvents; but it is soluble in hi hly fiuorinated solvents and can be coated from solutions therein. When the polymer is dissolved in a vo atile perfluoro solvent (for instance. c-CsFreO), or in Freon l13. any amount of Freon 12 can be dissolved therein without loss of miscibility; and such solutions can be employed in aerosol bomb tv e applicators for coating surfaces with the polymer. The liquid complexes can be employed in aerosol bomb type applicators for coating on surfaces, followed by olvmerization in situ.

Flexible self-sustaining polymer films can be made. Desp te its green color in bulk, thin coatings can be provided which produce no apparent coloration of the coated material. Polvmers of c mplexes that have been made using methanol as the reducin agent, are highly resistant to acids and bases and to oxidizing agents and reducing agents. and have a high degree of stability to chemical and. thermal decomposition. They are resist= ant to h t concentrated nitric acid but not to hot sulfuric acid. The polymers are transparent and have low refractive indices. which is of interest in respect to co tings and films were a low refractive index is desirable for optical reasons. Thus the polymer of the complex made from perfluorocaprvlic acid has a refracti e index of approximately 1.34. The polymers have a high electrical resistivity even at high humidities. which is of interest in respect to coating electrical insulators, spark plugs, etc, and in providing insulating coatings on wires and other electrical conductors. They are non-polar in nature have a low dielectric constant.

One of the most outstanding and valuable properties of these olymers and of coatings thereof is the combination of Water-repellency and oil-repellency (i. e. they are both hydrophobic and oleophobic). Continuous films have a low water-vapor permeability. Coatings are substantially as water-repellent as those provided by the best of the water-repellent coating agents heretofore on the market. The latter are not oil-repellent and are easily wetted by hydrocarbon oils and greases. The present polymers can be employed in much lower coating weights than hydrocarbon-type materials to obtain optimum water-repellency. In the prior art of waterproofing, it has been taken for granted that a hydrophobic characteristic is only obtainable in consequence of the presence of molecular groups that are not repellent to hydrocarbons and which may even have a strong afiinity thereto. The most strongly hydrophobic coatings have been readily wet by hydrocarbons. Conversely, in the art of oilproofing and greaseproofing it has been assumed that an elecphobic characteristic is only obtainable in consequence of the presence of molecular groups that are not repellent to water and which may even have a strong afiinity thereto. The most strongly oleophobic coatings have been readily wet by water.

Fabrics and paper treated with the present polymers, even when the coating weight is so low that no coloration and no stiffened handle is imparted, are remarkably impervious to both water-base and oil-base stains. Coffee, blood, ink, berry juice, cooking grease, motor oil, etc., can be blotted off, leaving little or no stain. They shed water like a ducks back but, unlike a ducks back, they also shed oil. An illustrative use is in treating neckties so as to render them resistant to staining due to dribbling of soup, gravy, coffee, fruit and vegetable juices, etc. a real boon to many men and their wives. The foreign material can be easily blotted off with a paper or cloth napkin or handkerchief. Another important feature is that the present complexes contain no chlorine and there is no evolution of HCl to contend with in setting-up coatings thereof, contrary to the case with various chlorine-containing waterproofing agents now on the market which must be used in a somewhat complicated and in a carefully controlled manner to minimize debilitation of the fibers by hydrochloric acid. Examples of textile materials that have been treated with good results are cotton, wool, silk, and synthetic materials including acetate and viscose rayons, nylon, and Orion. The treatment of textile fabrics will be discussed in further detail in a subsequent section.

In addition ot treating paper and textile products, the present chromium complexes (and their polymers) can be used generally for the surface treatment or coating of a great variety of materials with advantageous results, including hydrophilic materials such as metal, glass and ceramic products, asbestos, sand and other lithic materials, cellulosic films, wood, cork and leather.

They can be used to provide corrosion-resisting waterand-oil-repellent coatings on metals. ice formed in contact with such a treated surface has a low adhesion, indicating utility for treating the aluminum surfaces of airplane wings, etc. Glass articles can be treated to provide characteristics which are useful for window panes, Windshields, and lenses of electric flashlights, searchlights, automobile and aircraft headlights, taillights, etc. Glass filaments and fibers can be treated to exclude moisture and to provide tough and tightly bonded surface films that protect the glass from abrasion. Glass yarns and the like have the defect that the rubbing together of the glass filaments or fibers causes scratching of the surfaces which destroys the tensile strength of the scratched filaments or fibers.

Fabrics and papers impregnated with the present polymers, and self-sustaining polymer films, can be employed as oil-proof and water-proof gasket materials that are heat-resistant and chemically inert.

Metal, fiberboard, paper and glass containers can be coated on the inside to provide protection against materials shipped therein and in some cases to facilitate complete emptying due to the inner surface being nonwettable by the aqueous or non-aqueous contents, as, for example, lubricating oils, medicinals, etc. For instance, a glass bottle was provided on the inside with a polymer coating having a thickness of about 16* cm. and the bottle was filled with a viscous mineral oil, with the result that the oil could be poured out without leaving a residue, owing to the non-wetting of the treated glass surface.

The present complexes are also useful in providing primer coatings on glass, metal and other surfaces, which provide a better anchorage for subsequently applied fluorocarbon polymer coatings, owing to the fluorocarbon characteristic of the surface of such primer coatings. The best inter'oonding with the subsequent coating is obtained when the primer coating is fully cured after application of the further coating.

Isopropanol solutions of the present complexes have been blended with a variety of lacquers and enamels with the result: thatuthe' ultimate coatings h'ave":ac'c1uired Ia -:..-1.; o.o91 more ofzchromiumstrioitide in 1251-1111. otf'water, which was thenwamned 'to about60.".C.1: :There was then combination. ofxwater repellency and: oil-repellency; ..For

examplewa. melaminetypevenamel used. for coating re r. 1

frigeratorspwas rnodifiedfbyincorporating 'an isopropanol solutionioivthe complex:of perfluorocaprylic acid, and 5 ethyl acetate as atblendingragent, and wasthen .coated h on metals. and .heated to evaporate the solvents. poly-. merize thezcomplex, andlcure the enamel. The resultant enamel coatingwas both water-.repellentand oil-repellent. i

The weight. percent of thecompleX-(dry solids basis) Was. less thanwlt%;:.

Ammoniizted complexes-and polymers the reaction product complex was in its methanol-insoluble: 20.

tion canl-zbe followed by. the change in colorfrorn green to purple." :The fully ammoniated' complex contains two,

or possiblyrthree, ammonia molecules foreach chromium atom.

These ammoniated complexes-are very soluble in isopropanolu andva substantial proportion'of Water can be it insoluble inwisopropanolzi About one hour ormore of heating isrrequiredt' to render the product substantially i added towthe isopropanol solution Without causing precipitation,.theammoniated complex coming out of true solution as a finely-divided dispersion that remains stably suspended; =-This aqueous colloidal.solution can be used for coating andimpregnating. The ammoniated com-- plexes are insoluble in highly fiuorinated solvents;

The ammoniated complexes release ammoniaupon heating, the amount released dependingon the temperature andtthe time. 'Heating below '95-100 C. does'not cause lossxof ammonia'and results in a free-flowing purplish powder, having amelting point .of' 95-100 C.,

which is-insoluble in Water and in non-polar solvents, but is soluble inalcohol, acetone, ethyl acetate, and the ike. 5am.

Heatingat above lOOP C. and below about 180 C. yields a partially. ammoniated water-insoluble solid material which is very brittle,jpuiple-in color, and veryth'ermoplastic. has a softening .point of about 80 C.

water is the only hydroxylated compoundemployed. .wThe' .45 The product made from perfiuorocaprylic acid In appearance and. behavior this material when cooled resembles the asphaltic 1114316 1 p p ql of Such .plex can be diluted with water in at least a :50.1at1o materialuiGilsoniteP: It is soluble in acetone, methanol,

isopropanol, ethyl acetate, and the like, but is insoluble innon-polar: solvents.- Itis both hydrophobic and oleophobic.

Heating at a temperaturerof the order of 180 .C. is

required for complete .dearnmoniation, and results in .a

deep-greenl colored solid that is both waterrepellent and .perlluorocaprylic 21Cidil'L'6QIl1LlOf methanol; and stirring produce :refiuxingfthe boiling point'of'the solution was.

.about 80C.).': The entiremixture changedfromareda;- t 1 inc and diethylene glycol), sugar, acetone, formaldehyde;

water and the reducing: agent provide hydroxylated comes slowly added"a:.solution:of grams: (0.181. mole). of:

was iinmediatelystarted. 'Thetemperatureswas raised to dish brown to a deep green color. The green liquid-refs..- action product (chromium-perfiuoroacid complex) began to term at once but was not allowed to settle'out, being kept in suspension by stirring was to facilitate the release: 1; of acid dissolved therein, the latter reacting with-reduced chromium trioxide to form additionalrreactionproduct: All of the acid had reacted: with the chromiumtrioxide I by the end of about 20. minutes,'representing completion. ofthe reactionthereof in :a 2:1 molar ratio .of :acid to chromiumv trioxide,'the slight excesslof chromium trioxide remaining dissolvedinthezaqueous solution; At this stage stateiibutwas completely soluble in isopropanoL. =Heating; and stirring Werediscontinued and the green liquid product settled to' thebotto'm of the "flask as an'immiscible layer, which was withdrawn'throu'gh thetake-olf tube: This'is the finalproduct as ordinarily: prepared; 5 2

, (Continued heating at reflux for a .total period of-about 30 minutes will advance .thedegree'. of polymerization of the liquid product so that it isiabout soluble andi fit r completely insolublein isopropanol; but it is then still in. a liquid, though highlyviscid, state; not yet having be- '1 .come a solidpolymerJ 7 Instead of using methanohas' "the reducing agent, use we: can be made of other reducing agents as,rfor instance, ethanol, isopropanol, polyhydricalcohols (such' as glycer--' phenol, and hydroquinone. In all such casesbothvthe r pounds in the-reactionsystem'. -Anexampleof an ex-.. cellent inorganic reducing agent is sodium bisulfite (NaHSOs) and, When-this is'used as the sole reducing agent, the

use of isopropanolas the' reducing agent hasthe advantage of improving'the solubility"characteristics 'of the com-u plex, apparently due to therincorporation of =isopropanol" Without causing precipitation. 1 In contrastpthe addition of Water to an isopropanolsolution of a complexxthat has been made using methanol; causes immediate precipitation of'the complex."

oil-repellent, and is soluble in methanol, isopropanol, acetone, ethyl acetate, and the like, but is" insoluble in common non-polar.v solvents :It is. waxy and: soft at room temperature and isv very thermoplasticl't-is soluble in highly fluorinated solvents. r .1

Ammoniated-polymers'can be made by ammoniatingm. the polymers of the unammoniated complexes. This" can 1 be done by passing NH -through a solution of the polymer in a highly fiuorinatedsolvent. Owing to the, polymeric state of the materiah it maybe that only one. NHs mole-. cule is capable of being bonded for each chromium atom.

Preparation of complexes A general description has already been given of the:

manner fof preparing the present complexesrand their ammoniated derivatives.

The following is' a descriptionof a general procedure that has been employed in making the original unammoniatedmomplexes-and is illustrated by reference to the preparation of thechromium complex ofperiluoroca'prylie 'clroxylated 'reducingagent is used. Thus the chromium .complex has-beenunadeby reacting chromium trioxide mixture can he heatedto evaporate the-unreactedvolatiles,

preferred; it :is not essential. :The reaction medium "can' .be an anhydrous inert liquid vehicle containing "a" reducing agent, selected sothat the reactautsiare soluble inithe system andthe system containsa' hydroxylatedr compound. :in addition to' 'the acidJ Thusthe chromium complex.has

f vapor). In these procedures the chromium-perfluoroacid Although the use of an aqueous reaction medium is .s-r;

beenmadei by reacting chromium trioxide and the perfluoro acidin:carbon tetrachloride containing methanol'as" I the reducing agent): A reducing agent can-be employed?- per se asthe solvent vehicle, in which'case a liquid hy with theqierfluoroacid in a vehicle consisting solely-of i methanol in this situation the chromium trioxide should be added-'slowly and =very cautiously'toa solution of the acid in the m'ethanol' to avoid igniting-the methanol reactionproduct does not settle out per se. "The-reaction associated Withlthecomplex, thereby obtaining the desired 1 green liquid'xreactionproduct in'is'ola-ted form; o'r-the' lattercan be recovered by a solvent extractive procedurel u it is also possible ftou'se a:-chromium reactant thatalready contains chromium inits trivalent form when in'- troducedinto'the reaction'system. Forexample,:chr'omic acetate, .CrtCz'HsOzh'l-lzO, has bcen'em'ployed as the "chromium reactant in arWater-methanol(SO-:50 by vol- 2.1une) system, to which the perfluoro-acid was added; v =-'Upon boiling for about' 20-rninutes,'there was obtained a the flask to permit. the withdrawal-of .the liquid products-r The flask "wassurroundedby an. electrical heating mantle.

The flask was charged with a solution of 9.12 grams green liquid chromium-perfiuoro' acid complex having sub- *stantially 'th'e same properties previously mentioned,which- Was substantially insoluble in methanol but was soluble in isopropanol. This complex was heated to obtain a solid polymer that was both hydrophobic and oleophobic.

Similarly, use has been made of freshly precipitated chromic hydroxide, Cr(OH)3, as a chromium reactant containing trivalent chromium. Ordinary chromic sesquioxide, CrzOs, is unsuitable, apparently because of its insoluble and non-colloidal nature which prevents reaction at a practical rate.

Treatment of fabrics There are two principal methods for impregnating fabrics in accord with the present invention to provide water-repellency and oil-repellency.

The first method utilizes the isopropanol-soluble complexes, either in unammoniated or ammoniated form. The complex is dissolved in isopropanol. The final treating solution preferably contains about to 15 grams of the complex per liter of solution. When using the complex of perfluorocaprylic acid (CIFrsCOOI-I) for treating cotton cloth it has been found that the optimum concentration is 7.5l0 grams per liter; the optimum dry weight on the finished cloth being about 0.5 to 1.0%. (When treating cotton cloth a preliminary swelling of the fibers by steaming or kier-boiling is preferred.) The cloth is dipped into the solution and then is passed through rubber squeeze rolls to remove excess solution. The cloth is then oven-dried at 130 C. for to minutes when using the unammoniated complex, or for 1530 minutes when using the ammoniated complex, to cure the complex to its hydrophobic and oleophobic final form and evaporate the residual solvent. When using the ammoniated type of complex, or the unammoniated type of complex made with the use of isopropanol as the reducing agent, the isopropanol solution can be diluted with at least an equal volume of water. It will be noted that in this procedure the complex is heat-advanced and cured in situ directly on the fibers.

The second method utilizes the preformed or precured hydrophobic and oleophobic product of the complex, dissolved in a fluorinated solvent (such as c=CsFisO), in the same range of concentration noted above for the complex, and this solution is employed for impregnating the cloth. When the partially-deammoniated purple-colored material is employed it can be applied from solution in isopropanol, methanol, acetone or other suitable solvent. The fabric then only requires thorough drying of the solvent, leaving a thin coating on the fibers. This drying operation yields the best results it followed by a short heat cure (e. g., 10 minutes at 130 C.).

Both methods are preferably performed in a closed system and the solvent recovered for re-use.

This treatment produces no noticeable change in color, hand, flammability, porosity or tensile strength of the cloth.-

In experiments performed to evaluate the treatment as applie to a standard white cotton jeans fabric (kierboiled, 3.7 oz. per square yard, thread count of 96 x 64 per sq. in.), water repellency values of 26 to 28 were obtained using a variety of complexes and their polymers and the various treating procedures described above.

These values are the hydrostatic head values in centimeters as determined by the Well-known A. S. T. M. test No. D583-40T (also known as the A. A. T. C. C. hydrostatic pressure test). A value of 28 was obtained for all the polymers of the unammoniated complexes applied by the second method noted above, including the polymer of the complex of heptafluorobutyric acid (CsFvCOOI-I). These values approximate those obtained in comparison tests using Quilon and Zelan A, well-known waterproofing agents. The critical importance of fluorocarbon chain length was shown when comparison tests were made using the complex of trifluoroacetic acid (CFsCOOH) and its polymer, the values being in the range of l015, which do not represent significant water-repellency; the fibers being wetted by water.

There is no standard test for the measurement of oilrepellency of fabrics; indicating the uniqueness of this characteristic. The following empirical test, which has been found to yield significant and reproducible results, was employed: The treated fabric specimen is placed on a hard backing support inclined at 60 to the horizontal and a drop of Stanolind Oil (a pure petroleum oil) is placed on the specimen and comparative values are assigned based on the lengths of the run-off patterns.

A zero value indicates no run-01f, the drop being immediately absorbed. A value of indicates that the entire drop rolls down the incline without leaving any residual trail. The cloth samples treated with the complex of the C7F1sCOOI-I acid (or its polymer) showed a value of 80, the drop of oil running down the slope and leaving a discontinuous trail of spherical droplets which, upon blotting, left no stain on the cloth. Drops of oil placed on such treated cloth when in a horizontal position remained without penetration for indefinitely long periods. The polymers of the complexes of the CsFrCOOI-I and CsFeCOOH acids yielded treated cloths having nearly as high oil-repellency (a value of 70 on the scale employed). In contrast, cloth samples treated With the polymer of the complex of the CFaCOOH acid, and cloth samples treated with Quilon and Zelan A, showed no oil-repellency, the oil being rapidly absorbed and producing a marked stain.

I claim:

l. Chromium coordination complexes of the class consisting of: (A) water-insoluble green-colored tacky liquid complexes formed by the reaction, in an aqueous system, of a chlorine-free reactive compound containing trivalent chromium, and a perfiuoroalkyl monocarboxylic acid that has from 4 to 12 carbon atoms in the molecule, these complexes being free from chlorine and containing two perfiuoro acido groups for each chromium atom, and being capable of polymerization to a non-tacky solid polymer that is both hydrophobic and oleophobic; and (B) the ammoniated derivatives of the aforesaid complexes.

2. Compositions formed by heating the chromium complexes defined in claim 1 until they are in a hydrophobic and oleophobic solid state.

3. An article that is impregnated or coated with a composition specified in claim 2.

4. Chromium coordination complexes formed by the reaction, in an aqueous system, of a chlorine-free reactive compound containing trivalent chromium, and a perfluoroalkyl monocarboxylic acid that has from 4 to 12 carbon atoms in the molecule, these complexes being free from chlorine and containing two perfluoro acido groups for each chromium atom and being green-colored tacky liquid compositions that are insoluble in water and in methanol but are substantially completely soluble in isopropanol.

5. The ammoniated derivatives of the chromium complexes of claim 4.

6. Ammoniated solid polymers of the chromium complexes of claim 4.

7. Solid polymers of the class consisting of: (A) the non-tacky flexible solid polymers of the chromium complexes of claim 4, which are both hydrophobic and oleophobic; and (B) the ammoniated derivatives thereof.

8. An article that is impregnated or coated with a non-tacky, solid, hydrophobic and oleophobic, polymer of a chromium complex of claim 4.

9. A process which comprises preparing an aqueous solution containing chromium trioxide (CrOs) and a perfluoroalkyl monocarboxylic acid (C1LF21L+1COOH) that has from 4 to 12 carbon atoms in the molecule, the molar ratio being approximately 1:2, and which also contains a reducing agent for reducing the chromium to an active trivalent state; heating and mixing the solution until the green-colored liquid chromium-complex reaction product has advanced to a water-insoluble state that is insoluble in methanol but is soluble in isopropanol; and mechanically separating and recovering this product from the aqueous solution.

10. A proecss according to claim 9 wherein methanol is employed as a reducing agent. 11. A process according to claim 9 wherein isopropanol is employed as a reducing agent.

12. A process according to claim 9 wherein sodium bisulfite (NaI-ISOs) is employed as a reducing agent.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,118,772 Terres et al May 24, 1938 2,273,040 ller Feb. 17, 1942 2,549,220 McLaren Apr. 17, 1951 2,567,011 Diesslin et al Sept. 4, 1951 

1. CHROMIUM COORDINATION COMPLEXES OF THE CLASS CONSISTING OF: (A) WATER-INSOLUBLE GREEN-COLORED TACKY LIQUID COMPLEXED FORMED BY THE REACTION, IN AN AQUEOUS SYSTEM OF A CHLORINE-FREE REACTIVE COMPOUND CONTAINING TRIVALENT CHROMIUM, AND A PERFLUOROALKYL MONOCARBOXYLIC ACID THAT HAS FROM 4 TO 12 CARBON ATOMS IN THE MOLECULE, THESE COMPLEXES BEING FREE FROM CHLORINE AND CONTAINING TWO PERFLUORO ACIDO GROUPS FOR EACH CHROMIUM ATOM, AND BEING CAPABLE OF POLYMERIZATION TO A NON-TACKY SOLID POLYMER THAT IS BOTH HYDROPHOBIC AND OLEOPHOBIC; AND (B) THE AMMONIATED DERIVATIVES OF THE AFORESAID COMPLEXES. 